Alrighty everyone, I've tried searching and searching....but there are WAY too many threads with the words 'swap', 'between' and 'blackberry' in them!!

Seriously though, I'm currently on a TMO 8700 and am thinking of picking up a used 7105t to use in my pocket for weekend and 'formal' (i.e. wearing the tux) usage. Is it as simple as swapping the SIM between them and changing the PIN on the BIS? Anyone have any warnings or first hand experience?

Doug - I want to do exactly the same thing, but my Exchange is hosted. When you say "update the PIN on the BIS" did you mean the "BES"? If so, that involves a re-activation which our provider charges for...

Doug - I want to do exactly the same thing, but my Exchange is hosted. When you say "update the PIN on the BIS" did you mean the "BES"? If so, that involves a re-activation which our provider charges for...

No, he didn't mean BES. The OP specifically indicated that he uses BIS, not BES.
They are two different things.